1. Field of the Invention
The present invention concerns an apparatus and a method for the concentration and the determination of the concentration level of a particulate analyte (e.g., iron or sulfur compounds) in a moving liquid.
2. Description of Related Art
Techniques for monitoring and analysis of corrosion products have gone through several evolutionary stages in recent years. Sample collection by filtration of corrosion products is now supplemented by backup ion exchange membranes to capture both filterable as well as dissolved material. Analytical methods have progressed from quick and rough estimation using comparison charts, through element specific instrumental analysis, via atomic adsorption (AA) or inductively coupled plasma (ICP), to the rapid, multi-element methods of x-ray fluorescence spectroscopy.
Despite these refinements, corrosion product monitoring techniques continue to have the significant limitation that each individual analysis represents an integrated sample which, at best, gives only average concentration values for any particular sample collection period, which period may range from minutes to hours or days. The final analytical result lacks a distinction between: 1) a case of a steady rate of corrosion product transport, and 2) one by which transient instances of high corrosion product concentration account for the majority of the collection sample. This latter information, when it is available, would be useful to correlate in time with controllable parameters of the operating source of the particulate, i.e. the operating plant.
The present invention accomplishes the desired objectives by increasing the rate of sampling and analysis of corrosion products from hours or days to minutes to provide a more complete and more accurate time profile of the behavior of particulate analytes in a moving liquid.